Consider the following molecules or ions: ClO2+ , AsF6 - , IOF3,  and SOF2. Answer the following questions based on the Lewis structures and VSEPR theory prediction of their molecular shapes.

(a) Which one has only bond angles of 109.5°?

(b) Which one has only bond angles of 120°?

(c) Which one has bond angles of 90 and 180°?

(d) Which one has bond angles of 90, 120, and 180°?

1. Write a balanced chemical equation to describe the combustion reaction of methane (CH₄). Use standard enthalpies of formation to calculate the ΔH_rxn for the equation you wrote. If you burn enough methane to produce 1.6 × 10³ kJ of heat energy, how many liters of CO₂ would be produced at STP?

Gaseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water. Suppose 15.7 g of methane is mixed with 34. g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.

A water sample contains 150 mg/L ethylene glycol (C2H6O2) and 200 mg/L phenol (C6H6O). Calculate the COD and TOC.

After 1.60 mol of NH3 gas is placed in a 1600-cm^3 box at 25 degrees C, the box is heated to 500 K. At this temperature, the ammonia is partially decomposed to N2 and H2, and a pressure measurement gives 4.85 MPa. Find the number of moles of each component present at 500 K.

Using the paper, “Multiparametric Atomic Force Microscopy Imaging of Biomolecular and Cellular Systems”, describe what is meant by “Multiparametric AFM”.  Describe the impact and advantages of this approach. (Acc. Chem. Res. 2017, 50, 924−931)

Compare and contrast scanning tunneling microscopy (STM) and atomic force microscopy (AFM)? List at least two advantages and two disadvantages for both methods. Please reference at least one source in your discussion.

To calculate the isoelectric point of amino acids having other ionizable functional groups, we must also take into account the

pK_a

of the additional functional group in the side chain.

Indicate which

pK_a

values must be used to calculate the pI of the following amino acids: [1] aspartic acid; [2] arginine; [3] lysine. Be sure to answer all parts.

What additives may be used to prevent acid catalyzed hydrolysis of drugs containing ester moieties in drug formulations?

A buffer solution is made by dissolving .17g of ammonia and 1.07g ammonium chloride in enough water to make 250mL of solution

Detemine molarity of ammonium chloride

Detemine ammonium concentration

Determin solution molarity relative to ammonia

Determine solution pH

1. Discuss the applicatoin of distillation as a separation and purificatoin technique. Are there limits due to sample size, initial purity and final purity desired?

2. Discuss the applicatoin of gas chromatogrpahy as a separations and identification technique. Are there limits due to purity, sample size, phase of sample?

At 200 K, the compression factor of oxygen varies with pressure as shown in the table below. Evaluate the fugacity of oxygen at this temperature and 124 atm.

1. (a) What is the Na⁺ concentration in each of the following solutions:

2.85 M sodium sulfate:

2.18 M sodium carbonate:

0.985 M sodium bicarbonate:

(b) What is the concentration of a lithium carbonate solution that is 0.395 M in Li⁺? M

2. A sample of 0.7160 g of an unknown compound containing barium ions (Ba²⁺) is dissolved in water and treated with an excess of Na₂SO₄. If the mass of the BaSO₄ precipitate formed is 0.6894 g, what is the percent by mass of Ba in the original unknown compound?

3. A 0.9080 g sample of a mixture of NaCl and KCl is dissolved in water, and the solution is then treated with an excess of AgNO₃ to yield 1.953 g of AgCl. Calculate the percent by mass of each compound in the mixture.

% mass NaCl

% mass KCl

4. The concentration of lead ions (Pb²⁺) in a sample of polluted water that also contains nitrate ions (NO₃⁻) is determined by adding solid sodium sulfate (Na₂SO₄) to exactly 500 mL of the water. Calculate the molar concentration of Pb²⁺ if 0.00260 g of Na₂SO₄ was needed for the complete precipitation of lead ions as PbSO₄.

5. Consider the reaction

H₂(g) + Cl₂(g) → 2HCl(g) Δ H = −184.6 kJ/mol

If 5.0 moles of H₂ reacts with 5.0 moles of Cl₂ to form HCl at 1.0 atm, what is Δ U for this reaction? Assume the reaction goes to completion and Δ V = 0 L.
(The conversion factor is 1 L atm = 101.3 J.)

a)During an experiment, a student mixed 14.5mL of a 0.500 M sodium fluoride solution with 15.6 mL of a 0.750 M hydrofluoric acid solution the measured pH was 3.24.Calculate the pKa.b)Calculate th pH of a solution prepared by mixing 20.5 mL of a 0.500 M sodium flouride solution with 32.5 mL of a 0.750 M hydrofluoric acid solution. Use pKa from question 1

Aluminum chloride is made from aluminum metal and chlorine gas, as shown:

2Al(s) + 3Cl2(g) ---> 2AlCl3(s)

When 10.0g of aluminum and 25.0g of chlorine are reacted, 18.6g of aluminum chloride is formed. Determine:

a) the limiting reactant

b) the theoretical yield in grams

c) the percent yield for this reaction

d) the excess reactant in grams